Personalized tumor vaccine for pancreatic cancer

The Application of Dendritic Cells Vaccines in Tumor Therapy and Their Combination with Biomimetic Nanoparticles

Dendritic cells (DCs) act as a bridge between innate and adaptive immunity by presenting antigens to effector immune cells and have shown broad application potential in tumor immunotherapy. However, the clinical translation of DC vaccines encounters significant challenges, such as the immunosuppressive tumor microenvironment (TME) and the sub-optimal DC function and vaccine efficacy in vivo. In this review, our investigation has uncovered the latest developments in DC vaccines and their potential in cancer immunotherapy, with a special emphasis on the integration of nanotechnology. Several types of nanomaterials, including protein cage nanoparticles (NPs), biomimetic NPs, and targeted multifunctional NPs, have been developed to enhance the antigen presentation ability of DCs and their stimulatory effects on T cells. In addition, we have also summarized the synergistic anti-cancer effects of DC vaccines with immune checkpoint inhibitors, chemotherapy, and radiotherapy. In addition, recent advances in nanotechnology have made it possible to develop novel biomarkers that can enhance the antigen presentation capacity of DCs and stimulate T cells. These biomarkers not only improve the accuracy and precision of DC vaccine design but also provide new insights into understanding the mechanisms of the DC-mediated immune response. Despite challenges pertaining to technical complexities and individual adaptation in the design and production of DC vaccines, personalized immunotherapy based on DCs is expected to become an important part of cancer treatment with rapid developments in biotechnology and immunology. This review provides new perspectives and potential solutions for the optimal design and application of DC vaccines in cancer therapy.

A stumbling block in pancreatic cancer treatment: drug resistance signaling networks

The primary node molecules in the cell signaling network in cancer tissues are maladjusted and mutated in comparison to normal tissues, which promotes the occurrence and progression of cancer. Pancreatic cancer (PC) is a highly fatal cancer with increasing incidence and low five-year survival rates. Currently, there are several therapies that target cell signaling networks in PC. However, PC is a "cold tumor" with a unique immunosuppressive tumor microenvironment (poor effector T cell infiltration, low antigen specificity), and targeting a single gene or pathway is basically ineffective in clinical practice. Targeted matrix therapy, targeted metabolic therapy, targeted mutant gene therapy, immunosuppressive therapy, cancer vaccines, and other emerging therapies have shown great therapeutic potential, but results have been disappointing. Therefore, we summarize the identified and potential drug-resistant cell signaling networks aimed at overcoming barriers to existing PC therapies.

Nimbolide: A Potential Phytochemical Agent in Multimodal Pancreatic Cancer Therapies

A significant contributor to cancer-related death, pancreatic cancer (PC) has a terrible prognosis in general that has not altered over many years. Currently, it is extremely difficult to prevent disease or discover it early enough to initiate treatment. PC is a challenging malignancy to treat, and several major impediments significantly impact the effectiveness of its treatment. These obstacles primarily include chemoresistance, drug toxicity, and limited drug bioavailability. Phytochemicals can be used as an alternative to chemotherapeutic drugs, or they can augment the anticancer properties of the chemotherapeutic agents. Nimbolide (NL) is a prominent limonoid compound found in Azadirachta indica, and has garnered substantial attention as a phytochemical with anticancer potential. It has powerful antiproliferative effects on a variety of cancer cell lines and is effective as a chemotherapeutic in preclinical studies. The primary modes of action of NL include suppression of metastasis and angiogenesis, activation of apoptosis, anti-proliferation, and control of enzymes that metabolize carcinogens. Despite numerous pharmacodynamic (PD) investigations, NL is still in the early stages of the drug development process because no comprehensive pharmacokinetic studies or long-term toxicity studies. Preclinical and toxicological assessments should be conducted to establish an appropriate dosage range, ensuring the safety of NL for its application in initial human clinical trials. This review endeavors to provide a comprehensive summary of the current developmental stage of NL along with nanoparticles as a principal candidate for therapeutic purposes in PC.

Fusing a Novel Anti-CTLA-4 Nanobody to the IgG1 Fc Region Strengthens Its Ability to Induce CD8+ T Cell-Mediated Immune Responses Against Solid Tumors

Background

Our previously described a nanobody precisely targeting CTLA-4 and demonstrated that it can promote the antitumor response of adoptive T cells. Here we examined whether fusing it to the IgG1 Fc region would induce stronger, longer-lasting T-cell immune responses after exposure to the dendritic-tumor cell fusions.

Methods

The fusion of nanobody to Fc region was overexpressed in E. coli. Next, the proliferation, activation and cytotoxicity of the CD8+ T cells stimulated by the fusion protein and dendritic-tumor cell fusions was assessed in vitro, and the antitumor activity was evaluated in nude mice bearing xenografts of each type of solid tumor.

Results

Proliferation, activation and cytotoxicity of CD8+ T cells in vitro were significantly greater in the presence of the fusion protein than those in other groups. Consistently, different types of xenografts growth were significantly slower and animal survival significantly longer when the injected CD8+ T cells had been activated in vitro in the presence of the fusion protein.

Conclusion

Fusing our anti-CTLA-4 nanobody to the IgG1 Fc region potentiates its ability to induce strong, persistent CD8+ T cell responses against solid tumors in mice. This fusion strategy has the potential to realize clinical transformation and application to clinical treatment.

Revamping Hepatocellular Carcinoma Immunotherapy: The Advent of Microbial Neoantigen Vaccines

Immunotherapy has revolutionized the treatment paradigm for hepatocellular carcinoma (HCC). However, its efficacy varies significantly with each patient's genetic composition and the complex interactions with their microbiome, both of which are pivotal in shaping anti-tumor immunity. The emergence of microbial neoantigens, a novel class of tumor vaccines, heralds a transformative shift in HCC therapy. This review explores the untapped potential of microbial neoantigens as innovative tumor vaccines, poised to redefine current HCC treatment modalities. For instance, neoantigens derived from the microbiome have demonstrated the capacity to enhance anti-tumor immunity in colorectal cancer, suggesting similar applications in HCC. By harnessing these unique neoantigens, we propose a framework for a personalized immunotherapeutic response, aiming to deliver a more precise and potent treatment strategy for HCC. Leveraging these neoantigens could significantly advance personalized medicine, potentially revolutionizing patient outcomes in HCC therapy.

Progress in the development of vaccines for pancreatic adenocarcinoma

Pancreatic cancer, which is regarded as the third deadliest cancer globally, poses a significant challenge because of its limited range of treatment options and high mortality rate. Currently, there is a focus on both the development of a novel concept in vaccine designing and the parallel study of the associated immune mechanisms. To further our understanding of the healthcare field, a variety of promising designs have been introduced for in-depth study. The designs were developed to include the mKRAS-specific amphiphile vaccine, which targets a specific mutation in the KRAS gene in addition to the multi-antigen targeted DNA vaccine, which aims to stimulate an immune response against multiple cancer antigens. Furthermore, later designs of vaccines were introduced based on the development of peptide-based cancer vaccines, mRNA-based vaccines, cell-based vaccines, and engineered bacterial vectors using an oral Salmonella-based vaccine. The study presents the concept on which the new vaccine is based and discusses the up-to-date immunological manifestations of these designed vaccines.

IL-2 promotes expansion and intratumoral accumulation of tumor infiltrating dendritic cells in pancreatic cancer

This study aims to investigate the diagnostic potential of IL-2 for PDAC and develop a method to improve the dendritic cell (DC) based vaccine against PDAC. The gene expression data and clinical characteristics information for 178 patients with PDAC were obtained from The Cancer Genome Atlas (TCGA). DCs were isolated from Human peripheral blood mononuclear cells (PBMCs) and were cultured in 4 different conditions. DCs were pulsed by tumor cell lysates or KRAS G12D1 - 23 peptide, and then used to activate T cells. The mixture of DCs and T cells were administered to xenograft mouse model through the tail vein. The infiltration of DCs and T cells were detected by immunohistochemistry. The generation of KRAS G12D mutation specific cytotoxic T cells was determined by in vitro killing assay. We observed that PDAC patients with higher IL-2 mRNA levels exhibited improved overall survival and increased infiltration of CD8 + T cells, NK cells, naïve B cells, and resting myeloid DCs in the tumor microenvironment. IL-2 alone did not enhance DC proliferation, antigen uptake, or apoptosis inhibition unless co-cultured with PBMCs. DCs co-cultured with PBMCs in IL-2-containing medium demonstrated the strongest tumor repression effect in vitro and in vivo. Compared to DCs obtained through the traditional method (cultured in medium containing GM-CSF and IL-4), DCs cultured with PBMCs, and IL-2 exhibited increased tumor infiltration capacity, potentially facilitating sustained T cell immunity. DCs cultured in the PBMCs-IL-2 condition could promote the generation of cytotoxic T cells targeting tumor cells carrying KRAS G12D mutation.

Dynamics of intestinal and intratumoral microbiome signatures in genetically engineered mice and human pancreatic ductal adenocarcinoma

BACKGROUND

Emerging evidence has recently revealed a prominent role of the microbiome in pancreatic ductal adenocarcinoma (PDAC). However, while most observations were made in patients, mouse models still require a precise characterization of their disease-related microbiome to employ them for mechanistic and interventional preclinical studies.

METHODS

To investigate the fecal and tumoral microbiome of LSL-KrasG12D/+;LSL-Trp53R172H/+;Pdx-1-Cre (KPC) and control (CTRL) mice, Oxford Nanopore sequencing was applied. Feces were collected from 10 KPC mice and 10 CTRLs at 3 timepoints (6 weeks, 12 weeks, and when tumor-bearing (KPC) or 6 months (CTRL), respectively). Metagenomic sequencing was performed on feces DNA. KPC tumor and healthy pancreas DNA samples were subjected to 16S rRNA gene sequencing. Bacterial marker components were detected in KPC tumor tissue over time by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC).

RESULTS

Murine fecal samples showed a significantly different microbiome compared to age-matched healthy CTRLs regarding beta diversity (p = 0.001, R2 = 0.2-0.25 for Bray-Curtis). Adjusted human PDAC classifiers predicted disease status from feces of KPC mice achieving area under the receiver operating characteristic (AUROC) values of 80%. Furthermore, KPC tumors harbored significantly more bacterial components than healthy pancreas. Also the microbial composition differs significantly between KPC tumors and healthy pancreas tissue (p = 0.042 for Bray-Curtis). Microbiota found highly abundant in human PDAC samples were considerably more abundant in KPC tumors as compared to healthy pancreas samples (p-value <0.001).

CONCLUSION

KPC fecal samples show similarities with the microbial composition of stool samples from human PDAC patients.

Molecular and metabolic regulation of immunosuppression in metastatic pancreatic ductal adenocarcinoma

Immunosuppression is a hallmark of pancreatic ductal adenocarcinoma (PDAC), contributing to early metastasis and poor patient survival. Compared to the localized tumors, current standard-of-care therapies have failed to improve the survival of patients with metastatic PDAC, that necessecitates exploration of novel therapeutic approaches. While immunotherapies such as immune checkpoint blockade (ICB) and therapeutic vaccines have emerged as promising treatment modalities in certain cancers, limited responses have been achieved in PDAC. Therefore, specific mechanisms regulating the poor response to immunotherapy must be explored. The immunosuppressive microenvironment driven by oncogenic mutations, tumor secretome, non-coding RNAs, and tumor microbiome persists throughout PDAC progression, allowing neoplastic cells to grow locally and metastasize distantly. The metastatic cells escaping the host immune surveillance are unique in molecular, immunological, and metabolic characteristics. Following chemokine and exosomal guidance, these cells metastasize to the organ-specific pre-metastatic niches (PMNs) constituted by local resident cells, stromal fibroblasts, and suppressive immune cells, such as the metastasis-associated macrophages, neutrophils, and myeloid-derived suppressor cells. The metastatic immune microenvironment differs from primary tumors in stromal and immune cell composition, functionality, and metabolism. Thus far, multiple molecular and metabolic pathways, distinct from primary tumors, have been identified that dampen immune effector functions, confounding the immunotherapy response in metastatic PDAC. This review describes major immunoregulatory pathways that contribute to the metastatic progression and limit immunotherapy outcomes in PDAC. Overall, we highlight the therapeutic vulnerabilities attributable to immunosuppressive factors and discuss whether targeting these molecular and immunological "hot spots" could improve the outcomes of PDAC immunotherapies.

Genetic Mouse Models to Study Pancreatic Cancer-Induced Pain and Reduction in Well-Being

In addition to the poor prognosis, excruciating abdominal pain is a major challenge in pancreatic cancer. Neurotropism appears to be the underlying mechanism leading to neuronal invasion. However, there is a lack of animal models suitable for translationally bridging in vitro findings with clinical trials. We characterized KPC (KrasG12D/+; Trp53R172H/+; P48-Cre) and KPPC (KrasG12D/+; Trp53R172H/R172H; P48-Cre) mice with genetically determined pancreatic ductal adenocarcinoma (PDAC) and compared them with an orthotopic pancreatic cancer mouse model, healthy littermates and human tissue. We analyzed behavioral correlates of cancer-associated pain and well-being, and studied neuronal remodeling and cytokine expression. Histologically, we found similarities between KPC and KPPC tissue with human samples. Compared to healthy littermates, we detect nerve fiber hypertrophy, which was not restricted to a certain fiber type. Interestingly, while KPPC mice showed significantly reduced well-being, KPC mice emerged to be better suited for studying long-lasting cancer pain that emerges over a slow course of tumor progression. To address the neuroinflammatory correlate of loss of well-being, we studied cytokine levels in KPPC mice and observed a significant upregulation of CXCL16, TNFRSF5, CCL24, CXCL1, CCL22, CLL20 and CX2CL1. In summary, we demonstrate that the KPC mouse model is best suited to studying cancer pain, whereas the KPPC model can be employed to study cancer-associated reduction in well-being.